While attending an event at the San Antonio Botanical Garden last month, I was intrigued by Laura, a volunteer who was showing visitors the types of compost you should use (and should not use) in the garden when you have pets. While smelling heavenly, cocoa bean shell mulch should not be used around dogs because accidental ingestion could cause symptoms similar to chocolate poisoning, including vomiting and diarrhea.

One of her containers, however, contained pecan shell mulch. “This is a safe mulch to use in the garden around pets,” said Laura.

“But the shells have jagged edges,” I said. “Wouldn't that make it difficult for a dog or cat to walk on.”

“Yes, that's why some gardeners use it to keep cats out of their garden,” she said.

Intrigued that there might be a type of mulch that could deter cats from walking through a garden and dogs from digging in it, I planned to pass this humane tip along to my readers who had problems with animals in their yards.

But wait, there was more to the story.

Pecan shell mulch might deter dogs and cats, but it attracts squirrels. Laura said someone once told her they spread pecan shell mulch in their garden and the next day “about a million squirrels showed up to dig through the mulch and inspect the shells,” she said.

I couldn't stop laughing. Can you imagine spreading this mulch in your yard to deter cats and instead witness an army of squirrels descending on your yard? Thankfully, the squirrels left two days later and were not a bother again, she said. “But reconnaissance squirrels did visit every few days to re-check the mulch.”

The moral here: be careful what you wish for.

Dear Cathy: We're fostering a 3-year-old dog that has been given up several times for excessive barking and growling. We're having the same problem. She barks and growls at my husband and daughters. We hate to give up on her because it's possible this is the end of the line for her, but this is very difficult situation. Any thoughts?

A concerned foster mom

Dear Foster Mom: I don't know the severity of the growling, but dogs with severe behavior problems need to be assessed, provided behavior training and, if possible, placed in a foster care situation without kids around. If she is simply going from home to home without the appropriate interventions, she will likely get worse, not better. Ask the agency you're fostering for if they have the resources to help her succeed.

Send your pet stories and questions to Cathy M. Rosenthal, c/o Features Department, San Antonio Express-News, P.O. Box 2171, San Antonio, TX 78297-2171 or cathy@petpundit.com. Cathy's advice column runs every Sunday. You can read her blog, Animals Matter, at http://blog.mysanantonio.com/animals/. Cathy is the author of several children's books.